Riyadh
: Saudi Arabia's state airline has suspended its direct flights to Toronto after Canada called for the release of detained activists for civil society and women's rights.

In the evening of August 6, the airline, Saudia, made the announcement on its Twitter account that it was suspending flights from the August 13.

The news prompted users to ask how Saudis already on holiday in Canada were going to get back.

"Can I know how my family and I get back after the holiday?" one Twitter user asked Saudia. "We have a confirmed reservation and return tickets on August 24 from Toronto to !"

The moves were a stern rebuke to Canada after the country on August 3 expressed concern over the arrests of rights activists in Saudi Arabia, including prominent women's rights campaigner Samar Badawi, and called for their release.

said that amounted to "a blatant interference in the Kingdom's domestic affairs, against basic international norms and all international protocols."

Saudi Arabia's sudden sharp response to criticism shows the limits of reforms by Saudi Arabia's 32-year-old crown prince Mohammed bin Salman, who runs its day-to-day government. He has launched a campaign of social and economic change, but has not eased the absolute monarchy's total ban on political activism.

In recent months Saudi Arabia has lifted a ban on women driving, but it has also arrested activists, including more than a dozen high profile campaigners for women's rights.

Saudi Arabia has also frozen all trade over the "interference". Canada has responded by saying it "will continue to advocate for human rights".

Riyad has recalled its Saudi ambassador in Ottawa for consultations and expelled the Canadian ambassador in .

Saudi Arabia would also "put on hold all new business and investment transactions with Canada while retaining its right to take further action", it said. Trade between the two countries was worth $3bn in 2016.

All scholarships enabling Saudi students to study in Canada were also suspended, while students already in the country will be relocated.

It is unclear how many people this will affect. The Vancouver Sun said in 2015 that about 5,000 new students arrive from Saudi Arabia each year.